Drill bit



Jan. 29, 1924. 1,482,128 c. M.GODDARD ET AL DRILL BIT Filed June 5 1922gal!! a m j I gnuz'nl'oa Car/es J7 Goddard.

- William E, Powell.

Tim m g Patented Jan. 29, 1924.

UNrrEn stares 1,482,128 PATENT sales.

CHARLES M. oonnAan nn "WILLIAM E. POWELL, on nnnvnn, COLORADO.

DRILL BIT.

Application filed June 3, 1922. Serial No. 565,714.

To all whom it may concern:

Be it known that we, CHARLES M. Gon- DARD and WILLIAM E. POWELL citizensoi? the United States, residing at the city and county of Denver andState of Colorado. have invented certain new and useful Improvements inDrill Bits; and we do declare the following. to be a full, clear, andexact description otthe invention, such as will enable others skilledinthe art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, and to the characters of referencemarked thereon, which form a. part of this specification.

This invention relates todrills and has special reference to a drill bitadapted for use in coal mining. i

In mining coal it is necessary to bore holes of considerable size intothe coal in order to insert the explosives, and some times for otherpurposes. As the drills are operated by electricity or by compressedair, it is essential that they be so designed that they may be turnedwith a minimum amount of power so that the motor apparatus can be keptdown to a reasonable size and weight.

It is the object of this invention to produce a drill that shall be soconstructed that it will be capable of great speed and can be turnedwith a much smaller amount of power than drills of ordinary constructionand of the same effective diameter. I

The above and other objects that willbe readily apparent as thedescription proceeds are attained by means of a construction which wewill now describe in detail, reference being had for this purpose to theaccompanying drawings in which- Fig. 1 is a side elevation of our drillbit;

Fig. 2 is a vertical section thereof taken on line 22-, Fig. 3;

Fig. 3 is an elevation looking in the direction of the arrow 3 in Fig.1;

Fig. 4 is a section takeuon line 4lt, Fig. 1; and

5 Fig. 3.

The same reference numbers will be used is a section taken on'line 5-5,

to designate the same parts throughout the the coal.

per end corners removed by a diagonal cut. The lower endand by the termsupper and lower we have reference to the position in which the bit isshown on the drawing--- has a rectangular'recess 2 which is adapted toreceive a correspondingly shaped shank member 3 (Fig. 1) by means or"which the bit is rotated. The upper end of the bit has a hole lwhich mayhave astandard drill taper as shown, or which may be of any othersuitable cross section. Within hole t we place a drill 5, in themannerclearly shown in thedrawing. The opposite narrow sides are eachchannelled as indicated by numeralsG and 7,and within each chan nel weplace a cutter 8 which is held in place by a screw 9. These cutters areprovided with inclined ends 10 and have their front sides cut away inthe manner indicated by numeral 11, so as to form a cutting tooth 12.The upper end of the drill bit between the drill 5 and the cutters 8 isbeveled or inclined as indicated by numeral 13., and has secured theretosteel cutters 14 which are held in place by means of screws 15. Theupper end of each cutter 14 is beveled so as to form a cutting edge 16,the purpose of which will become readily apparent as the descriptionproceeds. On each of the wide or fiat sides we provide an elongatedridge 17 which extends diagonally across the sides in the manner shownin Fig. 1. The purpose of the ridge 17 is to move'thepowdered coaldownwardly oraway from the cutter towards the shank'member 3. p

The operation of our bit or cutter is as follows: The shank 3 is rotatedin the proper direction and drill 5 then cuts into When the drill 5 hasentered a short distance, the cutters 8 will strike the surface of thecoal and begin to cut a circular groove therein; this leaves a ring ofcoal between drill 5 and cutters 8. As the drill proceeds the cutters 14will engage the outer end of the coal ring and out th s.

away at the same speed at which the drill enters into the coal. Inthemanner just described, the drill will cut a clean hole at acomparatively fast speed and with the expenditure of a minimum amount ofpower. The drill 5 may be readily removed and ion sharpened or replaced,and the cutters 8 are made double ended so that when they become dullthey may be reversed, and

when both of the cutting edges become dull,

they may be reground.

In the above description we have referred to the portion 3 merely as ashank, but we want it understood that this shank is a portion of thetwisted auger stem which is usually employed in drills of this nature,as without the auger stem it would, of course, be impossible tooperatethe drill in holes of any considerable depth, as the powderedcoal would remain therein and prevent the stem from freely rotating.

Although we have laid particular stress 7 on the fact thatthis drill bitmay be operated with a smaller expenditure of power than ordinarily thecase for any drill of this size, it is of course understood that thisbit may be operated by hand as well as by air or electricity, andthe'ease with which it can be operated is just asimportant in the lattercase as in the former.

It is apparent from the above that we have devisedra drill bit that isespecially well adapted for use in drilling coal, and which is sodesigned that it can be operated at great speed and with a minimumexpenditure of power.

Having now described our what we claim is A device for drilling coalcomprising a body'member of substantially rectangular cross-section, achannel in each narrow side and extending parallel to the central axisof invention,

the member, aremovable cutter in each CHARLES M. GODDARD. WILLIAM E.POWELL

